基于非定常面元法的海上浮式风机气动性能研究

对于海上浮式风机而言,由于受到剪切风、塔影效应、浮式基础运动等因素的共同影响,其气动载荷会更加复杂,因此如何准确快速地对海上风力机的气动性能进行预估显得尤为重要。基于速度势的非定常面元法理论,研究海上浮式风机气动载荷特性,编制了相关的计算程序。以NREL 5 MW风机为例,建立了叶片和尾流的三维数值模型,计算得到了不同风速下风机的输出功率以及叶片表面的压力分布,对比数据结果分析了该方法的可靠性。针对非定常流动,模拟了剪切风和塔影效应的作用,并重点分析了浮式基础运动对风机气动载荷的影响。研究表明,浮式基础的纵荡和纵摇会增加输出功率的波动幅值,艏摇运动会导致单个叶片上的气动载荷产生较大的波动,为浮式风机叶片控制提供了参考。

Study on aerodynamic characteristics of floating wind turbines with unsteady panel method

For the offshore floating wind turbines, the aerodynamic load is affected by the shear wind and tower shadow effect, and the aerodynamic characteristics become more complicated under the motions of the floating platform. Therefore, how to estimate the aerodynamic performance of offshore wind turbines accurately and quickly is particularly important. The aerodynamic characteristics of offshore floating wind turbines are studied and the relevant calculation programs are compiled with the theory of potential based unsteady panel method. A three-dimensional numerical model of blades and wakes of NREL 5 MW wind turbines is established and the output power of the wind turbines and the pressure distribution on the blade surface at different wind speeds are calculated. The comparison data shows that the method is reliable. The effects of shear wind and tower shadow are simulated for unsteady flow and the influence of floating platform motion on aerodynamic load of wind turbines is analyzed. The research shows that the surge and pitch of the platform will increase the amplitude of the total output power and yaw will lead to obvious fluctuations in the aerodynamic load on a single blade, which provides a reference for the control of blades.